1. Field of the Invention
The present invention relates to a process for activating catalysts containing an S (sulfur)-containing organic additive, in particular a hydrotreating catalyst containing an S-containing organic additive.
2. Prior Art
Hydrotreating catalysts comprise hydrogenation metal components, generally a Group VI metal component such as molybdenum and/or tungsten and a Group VIII metal component, such as nickel and/or cobalt generally on an oxidic carrier. Hydrotreating catalysts containing S-containing organic additives are known in the art.
For example, European patent application 0 300 629 and European patent application No. 0 357 295 describe hydrotreating catalysts comprising a support impregnated with at least one member of molybdenum, tungsten, and/or Group VIII of the Periodic Table, and a mercapto-compound selected from mercaptocarboxylic acids, amino-substituted mercaptanes, di-mercaptanes, and thioacids.
European patent application No. 0 506 206 also describes a hydrotreating catalyst comprising an S-containing additive selected from the group of bi-mercaptanes, aminosubstituted mercaptanes, and thiocarboxylic acids. Some of the catalysts described in this reference are activated by a treatment with hydrogen at a temperature from room temperature up to 400° C. Similar subject-matter is described in European patent application No. 0 338 788, and European patent application No. 0 289 211.
U.S. Pat. No. 4,636,487 describes a hydrotreating catalyst comprising a support and a hydroxymercaptide of one or more metals, which may be the reaction product of a mercaptoalcohol and one or more metal compounds. The catalyst may be activated with hydrogen at a temperature of 66-316° C.
U.S. Pat. No. 5,139,990 describes a hydrotreating catalyst comprising a carrier and hydrogenation metal components which is treated with an aqueous medium comprising a water-soluble or water-miscible S-containing organic additive, followed by drying the resulting catalyst and activating it with hydrogen at a temperature of 100-600° C.
European patent application No. 0 496 592 describes a hydrotreating catalyst comprising a carboxylic acid and an organic sulfur compound which may be a mercaptocarboxylic acid.
WO 94/25157 is directed to a process for treating spontaneously combustible catalysts. It describes a process in which a catalyst is contacted with elemental sulfur and an oxygen-containing additive having at least 12 carbon atoms. The oxygen-containing additive is used to decrease the self-heating properties of the catalyst and improve sulfur retention.
As indicated above, many of the catalysts containing an S-containing organic additive are activated by being contacted with hydrogen. It has now been found that the activity of these catalysts can be increased if the catalyst is contacted with an organic liquid either prior to or simultaneous with the contacting with hydrogen.
Accordingly, in one embodiment, the present invention pertains to a process for activating a catalyst composition comprising at least one hydrogenation metal component of Group VI or Group VIII of the Periodic Table, and an S-containing organic additive, wherein the catalyst is contacted with hydrogen at a temperature between room temperature and about 600° C., and prior to or during the contacting with hydrogen the catalyst is contacted with an organic liquid.
In a second embodiment, our invention is a catalyst obtained by the above process.
In a third embodiment, our invention is a process for hydrotreating a hydrocarbon feed by contacting the feed with the above catalyst at hydrotreating conditions.
Other embodiments of our invention encompass details about reactant compositions, process steps and conditions, etc., all of which are hereinafter disclosed in the following discussion of each of the facets of our invention.